A 67-year-old Westport man and teacher at a Norwalk high school has been charged with sexually assaulting a child for whom he was babysitting, police said.

Victor Corso of Hillandale Road was taken into custody Monday, and charged with risk of injury to a child and fourth-degree sexual assault.

The incident took place when Corso was babysitting for the child at his home, police said. A sexual-abuse complaint about Corso was forwarded to police Dec. 26 from the state Department of Children and Families, and based on the police investigation, criminal charges were filed against Corso.